Should it be loose, or should it be fixed?

[the big mike]

hey guys, I'll try to just explain it in my best English because I can't upload a video of it right now.

Last weekend I was cleaning my chain and I noticed something weird:

When I hold my chain in the same spot, I can rotate my rear wheel like 30°. It's as if the sprocket and the rim aren't attached to each other.

Is this normal? and if it is: What's the use of it? To me, it seems like it would cause a bigger jolt when getting on the throttle...

[erbarry88]

If you're saying your chain goes from being tight to loose and vice versa then your chain is stretched out and it would be time to replace the chain and sprockets.
Posted via Mobile Device

[jeffreys24]

Should be fixed

[Motofool]

Originally Posted by the big mike

...It's as if the sprocket and the rim aren't attached to each other.

Correct, they are not attached, there is a rubber cushion in between.

See how to correct that slack:

http://faq.ninja250.org/wiki/How_to_shim_the_cush_drive

[CC Cowboy]

30 degress Fahrenheit or Celsius?

[Domagoj]

Originally Posted by the big mike

hey guys, I'll try to just explain it in my best English because I can't upload a video of it right now.

Last weekend I was cleaning my chain and I noticed something weird:

When I hold my chain in the same spot, I can rotate my rear wheel like 30°. It's as if the sprocket and the rim aren't attached to each other.

Is this normal? and if it is: What's the use of it? To me, it seems like it would cause a bigger jolt when getting on the throttle...

Wait, 30 as in thirty degrees of arc? You sure that the numbers are right?
That is simiar to not having a cushion in there at all, making the bike unridable ...

Hernan pointed you in the right direction though.

[the big mike]

Originally Posted by Motofool

Correct, they are not attached, there is a rubber cushion in between.

See how to correct that slack:

http://faq.ninja250.org/wiki/How_to_shim_the_cush_drive

Yes, this is what I mean. But why is it there?

I assume the cushion makes the transitions between throttle and no throttle softer. And so I would understand it if there was some play due to these cushions.

I remark however, that I can move my rear wheel without a lot of resistance over a not negligible angle. I should have it checked don't I
@Domagoj , 30° might be a little exaggerated, I'll try to make a video of it this weekend. It is rideable though
I've never really noticed it whilst riding. I always thought the jolt when getting on the throttle was normal because of a thread @akima once made (If I remember correctly)

However, I don't believe I'm in immediate danger and I stay on the throttle through turns. But I'll have it checked...
thanks for your help guys

[the big mike]

Originally Posted by CC Cowboy

30 degress Fahrenheit or Celsius?

I guess I shouldn't be feeding the troll, but whatever: You're kidding, right?

[the big mike]

Originally Posted by erbarry88

If you're saying your chain goes from being tight to loose and vice versa then your chain is stretched out and it would be time to replace the chain and sprockets.
Posted via Mobile Device

No that's not what I meant, it's what Motofool said

[Motofool]

With time and use, the rubber of the cushion shrinks, leaving some gaps between it and the aluminum of the wheel hub.

Since the sprocket and the wheel are rolling over different ball bearings, the relative movement feels very free.

The shims described in the link make a huge difference in fine throttle control at very low speeds; you would love the new feeling of more solid connection between engine and rear tire.

[akima]

Originally Posted by the big mike

I've never really noticed it whilst riding. I always thought the jolt when getting on the throttle was normal because of a thread @akima once made (If I remember correctly):

This!

I think what I've experienced sounds slightly different to what @"the big mike" is describing.

The engine feels extremely connected to the rear wheel on my bike; it's just the throttle that controls the engine that seems to jerk (as I described in my thread).

[choneofakind]

Originally Posted by akima

This!

I think what I've experienced sounds slightly different to what @"the big mike" is describing.

Your jerk is FI jerk. Carbs are analog: we US riders can have all shades of gray between on and off with the throttle. With an FI system, there is a certain point where the Throttle position sensor goes from on to off, making the bike have a very digital on/off feeling, and that's the jerk you feel. Am I correct in assuming that this on/off feeling is worst when you're at low rpm's and rolling on/off, like in a parking light, or staying in gear and putting up to a light? That's how mine is with my FI conversion. I get a little bit of that on/off feeling every once in a while. It's forced me to start being very gradual and smooth with my throttle. I've also started feathering the clutch a little more often.



Big mike - you can fix that cush drive my shimming like Hernan suggested. I did it and like it, as do many others here. It's cheap, easy, and reversible if you don't like it.

[akima]

Originally Posted by choneofakind

Your jerk is FI jerk. Carbs are analog: we US riders can have all shades of gray between on and off with the throttle. With an FI system, there is a certain point where the Throttle position sensor goes from on to off, making the bike have a very digital on/off feeling, and that's the jerk you feel. Am I correct in assuming that this on/off feeling is worst when you're at low rpm's and rolling on/off, like in a parking light, or staying in gear and putting up to a light? That's how mine is with my FI conversion. I get a little bit of that on/off feeling every once in a while. It's forced me to start being very gradual and smooth with my throttle. I've also started feathering the clutch a little more often.

Are you calling me a "FI jerk"?



To answer: I haven't noticed that low rpms make a difference. It's more to do with rolling off and then rolling back on again. Some pretty good explanations for this were provided by Chris in the thread I linked.

I doubt my issue is related to Mike's though, so we probs shouldn't discuss it further in his thread.

[the big mike]

Originally Posted by choneofakind

Your jerk is FI jerk. Carbs are analog: we US riders can have all shades of gray between on and off with the throttle. With an FI system, there is a certain point where the Throttle position sensor goes from on to off, making the bike have a very digital on/off feeling, and that's the jerk you feel. Am I correct in assuming that this on/off feeling is worst when you're at low rpm's and rolling on/off, like in a parking light, or staying in gear and putting up to a light? That's how mine is with my FI conversion. I get a little bit of that on/off feeling every once in a while. It's forced me to start being very gradual and smooth with my throttle. I've also started feathering the clutch a little more often.



Big mike - you can fix that cush drive my shimming like Hernan suggested. I did it and like it, as do many others here. It's cheap, easy, and reversible if you don't like it.

You are correct in every assumption you've made and I thank you for your advise